22491990 has 24 divisors (see below), whose sum is σ = 58479408. Its totient is φ = 5997840.

The previous prime is 22491983. The next prime is 22492009. The reversal of 22491990 is 9919422.

It is a super-2 number, since 2×22491990² = 1011779228320200, which contains 22 as substring.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 124866 + ... + 125045.

It is an arithmetic number, because the mean of its divisors is an integer number (2436642).

Almost surely, 2^22491990 is an apocalyptic number.

22491990 is an abundant number, since it is smaller than the sum of its proper divisors (35987418).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

22491990 is a wasteful number, since it uses less digits than its factorization.

22491990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 249924 (or 249921 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The square root of 22491990 is about 4742.5720869587. The cubic root of 22491990 is about 282.2773038055.

The spelling of 22491990 in words is "twenty-two million, four hundred ninety-one thousand, nine hundred ninety".